Scientists sifting through ancient sediments laid down just after Earth's most devastating episode of extinctions may have found minuscule fragments of the massive extraterrestrial object suspected to have caused the catastrophe.
About 250 million years ago, at the end of the Permian period, 95 percent of the species in the oceans and 70 percent of those on land went extinct (SN: 2/1/97, p. 74). That makes the famous mass extinction that wiped out the dinosaurs some 65 million years ago seem like a minor die-off. Previous chemical analyses of some gases and other matter in sediments deposited during the transition between the Permian and Triassic periods suggest that these materials came from outer space (SN: 2/24/01, p. 116: Extinctions Tied to Impact from Space). Now, researchers examining the same sediments have extracted microscopic fragments of metals and minerals that also bear an extraterrestrial fingerprint.